Gippsland Water Factory, Victoria, Australia

Scheduled for completion towards the end of 2008, the Gippsland Water Factory – an innovative wastewater treatment and recycling facility – will be the first of its kind in Australia.

With a capacity to treat 35 million litres daily, the plant will initially provide local industry with up to eight million litres of Class A recycled water. Ultimately, the intention is to recycle all of the water entering the plant.

The project is being delivered by the Gippsland Water Factory Alliance. The alliance was formed expressly to design, build and commission the plant and comprises Gippsland Water as principal sponsor with a consortium of three specialised companies: CH2M HILL, Parsons Brinckerhoff and Transfield Services.

In addition to the Water Factory itself, the work also calls for the construction of some 75km of allied pipelines and eight sewer pumping stations.

The project has an overall capital cost of A$174m.

BACKGROUND

The facility is principally being built to address a 50-year-old odour problem with the Regional Outfall Sewer – largely arising from an open-channel section which accounts for almost half of its 87km total length.

In addition to dealing with the ongoing environmental concerns this has inevitably caused, the recycled water will also prove beneficial to industry, with Australian Paper having already signed up to be the first customer.

It is hoped that the attraction of a secure source of high-quality recycled water will provide a boost to the local economy by encouraging commercial growth and generating new employment.

In the short-term, it has been estimated that around 300 people will be employed building the plant during the peak construction period.

Drawing heavily on green engineering to guide the plant’s design and approach to construction, the alliance sees the Water Factory as a key step in making the region a national leader of water sustainability and innovation.

To this end, the possibility of generating electricity on site to meet the plant’s operational needs is also being considered, while educational programmes and a visitor centre are planned to promote messages of sustainability.

The project will also help to protect and restore the region’s lakes and waterways.

PLANT DESIGN

Planning and design work began in January 2006, with construction starting thirteen months later.

Work is scheduled to be completed by the close of 2008, with a two-year commissioning period before Gippsland Water takes over full responsibility for the operation and maintenance of the facility in late 2010.

The treatment/reclamation process uses biological treatment, micro-filtration and finally, reverse osmosis. Twelve cells – each containing 216 membrane modules – form the core of the membrane filtration system, with eight dedicated to treating domestic wastewater and the remainder for industrial flows.

The membrane bioreactor (MBR) approach to be taken at the plant combines tried-and-tested Memcor membrane filtration with activated sludge treatment to enable the required standards for water re-use.

Overall process efficiency is improved significantly by the membranes’ high-retention of biosolids, which will enable them to be returned for improved biological treatment. The plant performance will be further enhanced by the use of low-pressure membranes within the biological reactor system.

This removes the requirement for sedimentation and media filtration to remove suspended solids or mixed liquor from the treated flow. As well as simplifying the whole procedure, this also reduces the overall footprint.

A further key feature of the Memcor design is the unique two-phase jet fluid renewal system, which has been designed to ensure that water, solids and air are evenly distributed within each membrane module. At the same time, the set-up’s cross-flow dynamics and cleaning arrangements minimise its energy demand.

The facility’s MBR will be housed within a doughnut-shaped structure.

The remaining treated water will continue to follow existing discharge arrangements, flowing along the Regional Outfall Sewer to reach the deep ocean outfall,1.2km from the shoreline.

KEY PLAYERS

Gippsland Water – the second-largest regional water authority in Victoria – is the principal sponsor, with project management being provided by Transfield Services and engineering services by CH2M HILL and Parsons Brinckerhoff.

The plant’s MBR system is being supplied by Siemens Memcor. Other local contractors involved include Boom Logistics, GBG Concreting, Morrow Plumbing, Nilsen and SM Urban.